News and information

Naked black hole has no stars, puzzling astronomers

Scientists were stunned to find a massive galaxy where one supermassive black hole was completely naked.

Astronomers working with the Hubble Space Telescope and the Chandra X-ray Observatory have made a stunning find. According to a report from Discovery News, researchers have been peering at a galaxy that contains two supermassive black holes. Unlike most black holes, however, one of them was caught “naked” – with no stars surrounding it.

The other black hole in the galaxy is completely surrounded by stars, which caused astronomers to scratch their heads. Researchers have been trying to come up with an explanation for the naked black hole, found in the galaxy SDSS J1126+2944.

Researchers believe that the strange phenomenon is the result of a galactic merger. Mergers happen when multiple galaxies collide and become swamped by each other’s relative gravitational forces. Stars tend to scatter when two galaxies collide before settling into position.

Supermassive black holes, which are typically found in the middle of galaxies, can also merge when two galaxies collide, creating a truly super-massive beast of a black hole.

In the case of SDSS J1126+2944, however, the two black holes within the galaxy still have yet to collide. According to investigator Julie Comerford, from the Colorado University, Boulder, “One black hole is starved of stars, and 500 times fewer stars associated with it than the other black hole. The question is why there’s such a discrepancy.”

Comerford, whose team presented their findings at the meeting of the American Astronomical Society in Kissimmee, FL this week, believes that there are two possible explanations for the black hole’s lack of stars. One theory is that tidal and gravitational forces scattered the black hole’s stars throughout the galaxy as they pass through the surrounding area.

Another theory suggests that the “stellar mass” of black holes may have something to do with the lack of stars. Astronomers have been searching for “intermediate mass black holes” in an attempt to find black holes that are currently in the process of growing more massive. These black holes are too big to have been formed by a supernova, and researchers believe they are the product of many small black holes merging over time. This would explain the lack of stars surrounding the naked black hole in SDSS J1126+2944, but astronomers still know little about the phenomenon.

A press release from the University of Colorado, Boulder describing the recent discovery can be found here.